U.S. patent number 9,683,569 [Application Number 14/837,945] was granted by the patent office on 2017-06-20 for compressor system having rotor with distributed coolant conduits and method.
This patent grant is currently assigned to Ingersoll-Rand Company. The grantee listed for this patent is INGERSOLL-RAND COMPANY. Invention is credited to James Christopher Collins, Stephen James Collins, Willie Dwayne Valentine.
United States Patent |
9,683,569 |
Collins , et al. |
June 20, 2017 |
Compressor system having rotor with distributed coolant conduits
and method
Abstract
A compressor includes a rotor having an outer compression
surface and a plurality of inner heat exchange surfaces. A coolant
supply manifold fluidly connects with a coolant inlet in a first
axial end of the rotor, and delivers coolant fluid by way of
conduits having an axial distribution in the rotor so as to deliver
coolant fluid to the heat exchange surfaces. The coolant may be a
refrigerant that undergoes a phase change within the rotor.
Inventors: |
Collins; James Christopher
(Mooresville, NC), Valentine; Willie Dwayne (Statesville,
NC), Collins; Stephen James (Mooresville, NC) |
Applicant: |
Name |
City |
State |
Country |
Type |
INGERSOLL-RAND COMPANY |
Davidson |
NC |
US |
|
|
Assignee: |
Ingersoll-Rand Company
(Davidson, NC)
|
Family
ID: |
56888925 |
Appl.
No.: |
14/837,945 |
Filed: |
August 27, 2015 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20170058896 A1 |
Mar 2, 2017 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04C
29/0007 (20130101); F04C 29/04 (20130101); F04C
18/16 (20130101); F04C 18/107 (20130101); F01C
21/08 (20130101) |
Current International
Class: |
F01C
21/04 (20060101); F04C 29/00 (20060101); F04C
18/107 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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102242711 |
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Jan 2014 |
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CN |
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1021530 |
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Dec 1957 |
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DE |
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1026399 |
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Aug 2000 |
|
EP |
|
690185 |
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Apr 1953 |
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GB |
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20060024818 |
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Mar 2006 |
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WO |
|
Other References
Jan. 31, 2017, European Search Report and Written Opinion, European
Patent Application No. 16185303.1, 9 pages. cited by
applicant.
|
Primary Examiner: Bogue; Jesse
Attorney, Agent or Firm: Taft Stettinius & Hollister
Claims
What is claimed is:
1. A compressor system comprising: a housing having formed therein
a gas inlet, a gas outlet, and a fluid conduit extending between
the gas inlet and the gas outlet; a rotor rotatable within the
housing about an axis of rotation, the rotor having an axial
direction associated with the axis of rotation and a
circumferential direction associated with a rotating motion about
the axis of rotation, and the rotor having an outer compression
surface exposed to the fluid conduit, a plurality of inner heat
exchange surfaces, and an outer body wall extending between the
outer compression surface and the plurality of inner heat exchange
surfaces; the rotor further including a first axial end having a
coolant inlet formed therein, a second axial end having a coolant
outlet formed therein, and a coolant manifold fluidly connected
with the coolant inlet; and the rotor further including a plurality
of coolant supply conduits having an axial and circumferential
distribution, and each extending outwardly from the coolant
manifold so as to supply a coolant to each of the plurality of
inner heat exchange surfaces at a plurality of axial and
circumferential locations, the rotor further including a plurality
of coolant exhaust conduits each coupled with individual ones of
the plurality of inner heat exchange surfaces, wherein separate
flow paths are defined through the plurality of coolant supply
conduits, plurality of inner heat exchange surfaces, and plurality
of coolant exhaust conduits where the plurality of inner heat
exchange surfaces extend between the plurality of coolant supply
conduits and plurality of coolant exhaust conduits.
2. The system of claim 1 wherein the coolant manifold and the
plurality of coolant supply conduits are formed in a one-piece
section of the rotor body.
3. The system of claim 1 wherein the coolant manifold includes a
coolant supply manifold, and the rotor further includes a coolant
exhaust manifold.
4. The system of claim 3 wherein the plurality of coolant exhaust
conduits having an axial and circumferential distribution and
extending inwardly to the coolant exhaust manifold.
5. The system of claim 4 wherein the coolant supply manifold and
the coolant exhaust manifold are overlapping in axial extent.
6. The system of claim 5 wherein the coolant supply manifold and
the coolant exhaust manifold are coaxial.
7. The system of claim 1 wherein the outer compression surface
forms a helical shape.
8. The system of claim 7 wherein the system includes a dual rotary
screw compressor comprising a second rotor in parallel with the
first rotor and intermeshed therewith.
9. The system of claim 1 wherein the plurality of coolant supply
conduits include terminal nozzle orifices oriented to spray coolant
onto the plurality of inner heat exchange surfaces.
10. A rotor for a compressor system comprising: a rotor body
defining a longitudinal axis extending between a first axial body
end and a second axial body end, the rotor body having an axial
direction associated with the longitudinal axis and a
circumferential direction associated with a rotating motion about
the longitudinal axis, and including an outer compression surface,
a plurality of inner heat exchange surfaces, and an outer body wall
extending between the outer compression surface and the plurality
of inner heat exchange surfaces; the rotor body further including a
coolant inlet formed in the first axial body end, a coolant outlet
formed in the second axial body end, and a coolant manifold fluidly
connected with the coolant inlet; and the rotor body further
including a plurality of coolant supply conduits having an axial
and circumferential distribution, and extending outwardly from the
coolant manifold so as to supply a coolant to the plurality of
inner heat exchange surfaces at a plurality of axial and
circumferential locations, the rotor body further including a
plurality of coolant exhaust conduits each coupled with individual
ones of the plurality of inner heat exchange surfaces, wherein flow
paths are defined through pairings of the plurality of coolant
supply conduits, plurality of inner heat exchange surfaces, and
plurality of coolant exhaust conduits where the plurality of inner
heat exchange surfaces extend between the plurality of coolant
supply conduits and plurality of coolant exhaust conduits.
11. The rotor of claim 10 wherein each of the first and second
axial body ends includes a cylindrical shaft end, for rotatably
journaling the rotor body in a compressor housing, and the outer
compression surface extending axially between the first and second
axial body ends and defining a helical shape.
12. The rotor of claim 11 wherein the plurality of inner heat
exchange surfaces includes a plurality of axially and
circumferentially advancing heat exchange surfaces each having an
arcuate shape.
13. The rotor of claim 11 wherein the coolant manifold and
plurality of coolant supply conduits are formed in a one-piece
section of the rotor body having a uniform material composition
throughout.
14. The rotor of claim 11 comprising a screw rotor where the outer
compression surface includes a plurality of helical lobes in an
alternating arrangement with a plurality of helical grooves.
15. The rotor of claim 10 wherein the coolant manifold includes a
coolant supply manifold, and further comprising a coolant exhaust
manifold overlapping in axial extent with the coolant supply
manifold, and a plurality of coolant exhaust conduits having an
axial and circumferential distribution and extending inwardly to
the coolant exhaust manifold.
16. The rotor of claim 15 wherein some of the coolant supply
conduits are positioned axially between coolant exhaust conduits
and the coolant outlet, and some of the coolant exhaust conduits
are positioned axially between coolant supply conduits and the
coolant inlet.
17. The rotor of claim 15 wherein at least some of the coolant
supply conduits pass through the coolant exhaust manifold.
18. A method of operating a fluid compressor comprising: rotating a
rotor within a compressor housing so as to compress a gas via
impingement of an outer compression surface of the rotor on the
gas, the rotor having an axial direction associated with an axis of
rotation about which the rotor is rotated and a circumferential
direction associated with the rotating the rotor about the axis of
rotation; conveying a coolant into a coolant manifold within the
rotor, and from the manifold to coolant supply conduits within the
rotor; and spraying a plurality of inner heat exchange surfaces of
the rotor with the coolant from the conduits at a plurality of
axially and circumferentially distributed locations, so as to
dissipate heat generated by the compression of the gas; and wherein
the conveying and spraying includes conveying and spraying a
refrigerant in liquid form that undergoes a phase change within the
rotor, and further comprising exhausting the refrigerant in gaseous
form from the rotor.
19. The method of claim 18 wherein the exhausting of the
refrigerant includes exhausting the refrigerant via a coolant
exhaust manifold that has an axial extent overlapping with an axial
extent of a coolant supply manifold supplying the plurality of
coolant supply conduits.
20. The method of claim 18 which further includes flowing coolant
through distinct flow paths defined by individual ones of the
plurality of coolant supply conduits, plurality of inner heat
exchange surfaces, and individual ones of a plurality of coolant
exhaust conduits where the plurality of inner heat exchange
surfaces extend between the plurality of coolant supply conduits
and plurality of coolant exhaust conduits, and wherein the
plurality of coolant exhaust conduits have an axial and
circumferential distribution and extend inwardly to a coolant
exhaust manifold.
Description
TECHNICAL FIELD
The present disclosure relates generally to compressor rotors, and
more particularly to compressor rotor cooling.
BACKGROUND
A wide variety of compressor systems are used for compressing gas.
Piston compressors, axial compressors, centrifugal compressors and
rotary screw compressors are all well-known and widely used.
Compressing gas produces heat, and with increased gas temperature
the compression process can suffer in efficiency. Removing heat
during the compression process can improve efficiency. Moreover,
compressor equipment can suffer from fatigue or performance
degradation where temperatures are uncontrolled. For these reasons,
compressors are commonly equipped with cooling mechanisms.
Compressor cooling generally is achieved by way of introducing a
coolant fluid into the gas to be compressed and/or cooling the
compressor equipment itself via internal coolant fluid passages,
radiators and the like. Compressor equipment cooling strategies
suffer from various disadvantages relative to certain
applications.
SUMMARY
A compressor system includes a housing and a rotor rotatable within
the housing. The housing has a coolant inlet, a coolant outlet, and
a coolant manifold fluidly connected with the coolant inlet. The
rotor further has coolant delivery conduits with an axial and
circumferential distribution, that extend outwardly from the
manifold to supply coolant fluid to inner heat exchange surfaces of
the rotor.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a partially sectioned diagrammatic view of a compressor
system according to one embodiment;
FIG. 2 is a sectioned view of a rotor suitable for use in a
compressor system as in FIG. 1, according to one embodiment;
FIG. 3 is a partial, negative image view of a rotor, according to
one embodiment;
FIG. 4 is a partial, negative image view of internal cooling
passages in a rotor, according to one embodiment;
FIG. 5 is a sectioned view of a rotor suitable for use in a
compressor system as in FIG. 1, according to one embodiment;
FIG. 6 is a sectioned view taken along line 6-6 of FIG. 5;
FIG. 7 is a sectioned view taken along line 7-7 of FIG. 5; and
FIG. 8 is a sectioned view taken along line 8-8 of FIG. 5.
DETAILED DESCRIPTION OF THE FIGURES
For the purposes of promoting an understanding of the principles of
the Compressor System Having Rotor With Distributed Coolant
Conduits And Method, reference will now be made to the embodiments
illustrated in the drawings and specific language will be used to
describe the same. It will nevertheless be understood that no
limitation of the scope of the invention is thereby intended. Any
alterations and further modifications in the described embodiments,
and any further applications of the principles of the invention as
described herein are contemplated as would normally occur to one
skilled in the art to which the invention relates.
Referring to FIG. 1, there is shown a compressor system 10
according to one embodiment and including a compressor 12, a
compressed air powered device or storage vessel 14, and a cooling
system having a coolant loop 16, a coolant pump 18 and a radiator
20 or the like. Compressor 12 may be of the dual or twin rotary
screw type, as further discussed herein, although the present
disclosure is not thusly limited. Compressor 12 includes a
compressor housing 22 having formed therein a gas inlet 24, a gas
outlet 26, and a fluid conduit 28 extending between gas inlet 24
and gas outlet 26. A rotor 30 is rotatable within housing 22 about
an axis of rotation 31 to compress gas conveyed between gas inlet
24 and gas outlet 26. In the illustrated embodiment, compressor 12
includes rotor 30 and also a second rotor 132 rotatable about a
second and parallel axis of rotation 133. While rotors 30 and 132
are shown having similar configurations, it should be appreciated
that dual rotary screw compressors according to the present
disclosure will typically include a male rotor and a female rotor,
example features of which are further described herein. Except
where otherwise indicated, the present description of one of rotors
30 and 132, and any of the other rotors discussed herein, should be
understood as generally applicable to the present disclosure. As
will be further apparent from the following description, by virtue
of unique cooling strategies and rotor construction the present
disclosure is expected to be advantageous respecting system
reliability and operation, as well as efficiency in compressing
gasses such as air, natural gas, or others.
Rotor 30 includes an outer compression surface 36 exposed to fluid
conduit 28, and at least one inner heat exchange surface 38. In a
practical implementation strategy, rotor 30 includes a screw rotor
where outer compression surface 36 includes a plurality of helical
lobes 35 in an alternating arrangement with a plurality of helical
grooves 37. As noted above, rotor 30 may be one of a male rotor and
a female rotor, and rotor 132 may be the other of a male rotor and
a female rotor. To this end, in a known manner lobes 35 might have
a generally convex cross-sectional profile formed by convex sides,
where rotor 30 is male. In contrast, where structured as female
rotor 132 may have concave or undercut side surfaces forming the
lobes. Lobes 35 and grooves 37 might be any configuration or number
without departing from the present disclosure, so long as they have
a generally axially advancing orientation sufficient to enable
impingement of outer compression surface 36 on gas within fluid
conduit 28 when rotor 30 rotates.
Rotor 30 may further include an outer body wall 40 extending
between outer compression surface 36 and inner heat exchange
surface 38. During operation, the compression of gas via rotation
of rotor 30 generates heat, which is conducted into material from
which rotor 30 is formed. Heat will thus be conducted through wall
40 from outer compression surface 36 to heat exchange surface 38.
Rotor 30 further includes a first axial end 42 having a coolant
inlet 44 formed therein, and a second axial end 46 having a coolant
outlet 48 formed therein. A coolant manifold 60 fluidly connects
with coolant inlet 44. Each of first and second axial ends 42 and
46 may include a cylindrical shaft end having a cylindrical outer
surface 50 and 52, respectively. Journal and/or thrust bearings 51
and 53 are positioned upon axial ends 42 and 46, respectively, to
react axial and non-axial loads and to support rotor 30 for
rotation within housing 22 in a conventional manner.
As mentioned above, heat is conducted through wall 40 and otherwise
into material of rotor 30. Coolant may be conveyed, such as by
pumping, into coolant inlet 44, and thenceforth into manifold 60.
Suitable coolants include conventional refrigerant fluids, gasses
of other types, water, chilled brine, or any other suitable fluid
of gaseous or liquid form that can be conveyed through rotor 30.
Rotor 30 also includes a plurality of coolant supply conduits 62
having an axial and circumferential distribution. Conduits 62
extend outwardly from coolant manifold 60 so as to deliver a
coolant to heat exchange surface 38 at a plurality of axial and
circumferential locations. As will be further apparent from the
following description, rotor 30 might have many inner heat exchange
surfaces, or only a single inner heat exchange surface. In a
practical implementation strategy, material from which rotor body
34 is made will typically extend continuously between heat exchange
surface 38 and outer compression surface 36, such that the
respective surfaces could fairly be understood to be located at
least in part upon outer body wall 40. Also in a practical
implementation strategy, rotor body 34 is a one-piece rotor body or
includes a one-piece section wherein coolant manifold 60 and
conduits 62 are formed. In certain instances, rotor body 30 or the
one-piece section may have a uniform material composition
throughout. It is contemplated that rotor 30 can be formed by
material deposition as in a 3D printing or other additive
manufacturing process. Those skilled in the art will be familiar
with uniform material composition in one-piece components that is
commonly produced by 3D printing. It should also be appreciated
that in alternative embodiments, rather than a uniform material
composition 3D printing capabilities might be leveraged so as to
deposit different types of materials in rotor body 34 or in parts
thereof. Analogously, embodiments are contemplated where rotor body
34 is formed from several pieces irreversibly attached together,
such as by friction welding or any other suitable process.
Returning to the subject of coolant delivery and distribution, as
noted above coolant is delivered to the one or more heat exchange
surfaces 38 at a plurality of axial and circumferential locations.
From FIG. 1 it can be seen that conduits 62 are at a plurality of
different axial locations, and also a plurality of different
circumferential locations, relative to axis 31. It can further be
seen that conduits 62 may be structured such that they narrow in
diameter near surface 38 so as to form orifices. Whether or not
such narrowing is used in a production embodiment can vary,
however, the coolant can be understood to be sprayed in at least
certain instances upon heat exchange surface or the multiple heat
exchange surfaces 38 at the plurality of axial and circumferential
locations. Where a refrigerant is used, the refrigerant may undergo
a phase change within rotor 30, transitioning from a liquid form to
a gaseous form and absorbing heat in the process. In other
instances, refrigerant might be provided or supplied into rotor 30
in a gaseous form, still potentially at a temperature below a
freezing point of water, or within another suitable temperature
range, depending upon cooling requirements.
Referring also now to FIG. 2, there is shown a sectioned view of
rotor 30 illustrating additional details, and also including
geometry less diagrammatic in form than the geometry shown in FIG.
1. The generally helical shape of lobes 35 and grooves 37 is
apparent in FIG. 2, as defined by surface 36. It can also be seen
from FIG. 2 that multiple heat exchange surfaces 38 may be formed
within a plurality of channels 80 for coolant, some of the channels
being shown and visible in the cross-sectional view of FIG. 2 and
others hidden. Surfaces 38 may have a generally arcuate shape that
tracks the arcuate shape of channels 80, being axially and
circumferentially advancing and tracking the arcuate and helical
shape of lobes 35. As will be further apparent from the following
description and additional drawings to be described, channels 80
may be each fed by a conduit 62, and arc about axis 31 while
axially advancing within rotor body 34, and each typically but not
necessarily traversing less than one full turn about axis 31.
In a practical implementation strategy, manifold 60 may include a
coolant supply manifold, and rotor 30 may further include a coolant
exhaust manifold 70 as shown in FIGS. 1 and 2. It can further be
seen that exhaust manifold 70 and coolant supply manifold 60 are
overlapping in axial extent. This means that certain axial
locations, or an axial range of locations in rotor 30, are occupied
by both supply manifold 60 and exhaust manifold 70. In a further
practical implementation strategy, supply manifold 60 and exhaust
manifold 70 are coaxial, with supply manifold 60 being radially
outward from exhaust manifold 70. Another way to understand the
relationship between supply manifold 60 and exhaust manifold 70 is
that exhaust manifold 70 is positioned at least partially within
supply manifold 60. It can be seen from FIG. 2 that supply manifold
60 may have a generally annular configuration and extends about
exhaust manifold 70. Other configurations are certainly
contemplated within the scope of the present disclosure, and supply
manifold 60 and exhaust manifold 70 could in other embodiments be
side by side rather than one within the other. It has been
discovered that the overlapping axial extent of supply manifold 60
and exhaust manifold 70, and the overlapping axial distributions of
coolant supply and coolant withdrawal in rotor 30, is advantageous
with respect to thermal management and heat dissipation. In a
practical implementation strategy, some of coolant supply conduits
62 may be positioned axially between some coolant exhaust outlets
72 and coolant outlet 48. Some of coolant exhaust conduits 72 may
be positioned axially between some coolant supply conduits 62 and
coolant inlet 44. Stated another way, cold coolant may be sprayed
onto surfaces 38 at locations closer to axial end 46 than some of
the locations where coolant is withdrawn after having exchanged
heat with surfaces 38. While the present disclosure is not strictly
limited as such, this configuration can help ensure that nowhere
along the axial length of rotor 30 will the coolant actually be
hotter than the air external to rotor 30 that is being compressed.
At least some coolant delivery conduits 62 may pass radially
through coolant exhaust manifold 70, as evident in FIGS. 1 and
2.
Referring also now to FIG. 3, there is shown a negative image view
of fluid passages within rotor body 34. In other words, the
illustration in FIG. 3 shows in solid form features which are
actually voids in rotor 30. It can be seen that a plurality of
coolant supply conduits 62 extend radially outward from manifold 60
to channels 80. The arcuate shape of channels 80 is also readily
apparent in FIG. 3. It can also be seen that some of conduits 62
branch so as to feed more than one channel 80. After the coolant
passes through channels 80, and in the case of a refrigerant
potentially changing phase, the coolant will pass through coolant
exhaust conduits 72 and make its way back to exhaust manifold 70.
In the FIG. 3 illustration only a relatively small part of exhaust
manifold 70 is visible, and none of it might be visible, as conduit
70 is typically internal or in part internal to conduit 60. A
branch 64 in one of conduits 62 is shown where multiple channels 80
are fed originally by a single conduit 62 from manifold 60. Turning
also to FIG. 4, there is shown a partial view again including a
negative image showing certain features of rotor 30 in solid form
where those features are actually voids or cavities within rotor
body 34. The generally curving nature of some of exhaust conduits
72, the branching of exhaust conduits 72, and the axial and
circumferential distribution of exhaust conduits 72 as they extend
inwardly to manifold 70 are readily apparent in FIG. 4. Some of the
coolant passage features of rotor 30 are omitted from the FIG. 4
illustration for purposes of clarity.
Referring now to FIG. 5, there is shown a sectioned side view of a
rotor 132 of similar form to rotor 132 of FIG. 1 and accordingly
illustrated with the same reference numerals. Rotor 132 includes a
plurality of helical lobes 135 in an alternating arrangement with
helical grooves 137, axially advancing along a rotor body 134.
Rotor 132 may be of a female rotor form, where grooves 137 and
lobes 135 are structured to enmesh with counterpart male lobes and
grooves as in rotor 30, and where lobes 135 are undercut
approximately as shown in FIG. 5. Rotor 132 also includes a
manifold 160 for supply of coolant, and a coolant exhaust manifold
170. A plurality of coolant supply conduits 162 convey coolant from
manifold 160 to channels 180 wherein heat exchange surfaces 138 are
located, generally analogous to rotor 30. Exhaust conduits 172 are
structured to convey coolant from channels 180 to exhaust conduit
170, and thenceforth out of rotor 132 such as for cooling
compression and recirculation.
Rotor 132 as in FIG. 5 has certain similarities with rotor 30
discussed above, but certain differences. Referring now to FIG. 6,
there is shown a sectioned view taken along line 6-6 of FIG. 5
wherein coolant supply conduits 162 are shown extending radially
outward from supply manifold 160. In the view of FIG. 6 it can be
seen that manifold 160 extends around manifold 170. The particular
sectioned view of FIG. 6 extends also through exhaust conduits 172.
It will thus be understood that channels or the like 180 extend
between conduits 162 and conduits 172. Channels 180 may each be
curved between an inlet end fed by a supply conduit 162 and an
outlet end feeding an exhaust conduit 172. Referring also to FIG.
7, there is shown a sectioned view taken along line 7-7 of FIG. 5.
Channels 180 are evident in FIG. 7, and shown being fed via coolant
with conduits 162. Narrowing of conduits 162 at radially outward
locations to form spray orifices is also visible. Referring also to
FIG. 8, there is shown a sectioned view taken along line 8-8 of
FIG. 5, where it can be seen that tips or ends of channels 180 are
joined to conduits 172, feeding coolant having exchanged heat with
surfaces 138 into conduits 172, and thenceforth into manifold 170
for removal from rotor 132.
Operating compressor system 10 and compressor 12 according to the
present disclosure will generally occur analogously in each of the
embodiments contemplated herein. Accordingly, the present
description of rotor 30 should be understood to generally apply to
any of the rotors contemplated herein. Rotor 30 may be rotated to
compress a gas within housing 14 via impingement of outer
compression surface 36 on the gas in a generally known manner.
During rotating rotor 30, coolant may be conveyed into coolant
manifold 60 within rotor 30, and from manifold 60 to coolant supply
conduits 62. Heat exchange surface 38 may be sprayed with coolant
from conduits 62 at a plurality of axially and circumferentially
distributed locations, so as to dissipate heat that is generated by
the compression of the gas. As noted above, the conveying and
spraying may include conveying and spraying a refrigerant in liquid
form that undergoes a phase change within rotor 30, which is then
exhausted in gaseous form from rotor 30. The present disclosure is
not limited as such, however, and other coolants and cooling
schemes might be used.
The present description is for illustrative purposes only, and
should not be construed to narrow the breadth of the present
disclosure in any way. Thus, those skilled in the art will
appreciate that various modifications might be made to the
presently disclosed embodiments without departing from the full and
fair scope and spirit of the present disclosure. Other aspects,
features and advantages will be apparent upon an examination of the
attached drawings and appended claims.
* * * * *